1. Field of the Invention
The present invention relates to a zoom lens having a high variable magnification ratio used in electronic cameras such as digital cameras, video cameras, broadcasting cameras, surveillance cameras and the like, and to an imaging apparatus including the zoom lens.
2. Description of the Related Art
Conventionally, a zoom lens substantially consists of: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group having positive refractive power; and a fifth lens group having negative refractive power, which are arranged in this order from the object side, is known as a zoom lens having relatively a high variable magnification ratio. The zoom lens with such a lens construction is known to be appropriate for realizing both a high variable magnification ratio and a reduction in size (see Japanese Unexamined Patent Publication No. 4(1992)-070707, Japanese Unexamined Patent Publication No. 9(1997)-197271, and Japanese Unexamined Patent Publication No. 11(1999)-064728).